Thread: AR2209 Lot Variations in the 6.5 x 55.

[QUOTE=JaSa;984132]H4350 aka AR2209 has a 0.29fps increase per degree F.
I don't do F so in Celsius lets say in winter you go hunting at 0 Celsius and in summer you go out in 40 Celsius, the increase in speed will be 19fps

Source

In terms of the 6.5 x 55 it will mean you will go from -46in to -45.3in drop at 500m with the 120gr GMX




Ok i get your point re seasonal variation probably not being greater than say 20. But i do shoot in strings in 12deg and then get my chamber/barrel too hot to touch so im assuming thats going from 12deg c up to + 50c or hotter. At 800m that is amounting to something of a substantial shift in MV. Given that change in MV i have witnessed over a chrony (and not a keyboard) might be the barrel / expansion / altered distance to lands i dont know. Always assumed it was the temp of the powder baking away in the chamber if i left it too long to shoot after a string.